A bomb was on Wednesday found planted near the US Embassy premises at Maharajgunj in the outskirt of the city.
Security personnel surrounded the area after a suspected unattended bag was found near the embassy building, police said.
The special bomb disposal squad was called in, who defused the pressure cooker bomb, they said.
Police recovered pamphlets of Krantikari Janabadi Morcha, a lesser-known group, from the site.
Security has been beefed up further in and around the US Embassy after the incident, officials said.